scholarly journals Leaf growth under temperature and light control

2009 ◽  
Vol 55 (No. 12) ◽  
pp. 551-557 ◽  
Author(s):  
J. Repková ◽  
M. Brestič ◽  
K. Olšovská
Keyword(s):  
Leaf Growth ◽  
Leaf Length ◽  
Leaf Expansion ◽  
Main Stem ◽  
Leaf Position ◽  
Temperature Sum ◽  
Air Temperatures ◽  
Strong Relation ◽  
Accumulated Temperature ◽  
Leaf Appearance

Dynamics of crop growth and photosynthesis are two main processes that are of major importance for adaptation of plants to their environment. Two experiments were carried out during 2005 and 2006 with sun and shaded barley plants. The results showed that leaf area increased with leaf position on the main stem up to leaf position 5 for sun and leaf position 6 for shaded plants, and then declined towards flag leaves. Air temperature affected leaf appearance, mainly at the beginning of the growing season. A positive correlation between leaf expansion duration (LED) and accumulated temperature sum was measured for both variants, LED linearly increased with temperature sum. Leaf expansion rate (LER) showed a similar dependence on accumulated air temperatures in both light variants. A strong relation was found between soil temperature and LER for the first four leaves of the main stem of shaded plants in 2006. In shaded environment the higher LER was associated with lower accumulated irradiance sum when light restriction supported an increase of leaf elongation and final leaf length.

Stem and leaf growth of alpine sun and prairie shade ecotypes of Stellaria longipes under different photoperiods: role of ethylene

2006 ◽  
Vol 84 (9) ◽  
pp. 1496-1502 ◽  
Author(s):  
Linda J. Walton ◽  
Leonid V. Kurepin ◽  
David M. Reid ◽  
C.C. Chinnappa
Keyword(s):  
Leaf Growth ◽  
Stem Elongation ◽  
Leaf Length ◽  
Leaf Expansion ◽  
Alpine Plants ◽  
Growth Responses ◽  
Stellaria Longipes ◽  
Length And Area ◽  
Radiation Conditions

Plant ecotypes of Stellaria longipes Goldie from competitive, shade-adapted prairie habitat and less competitive, nonshaded alpine habitat were subjected to shortened or extended photoperiod conditions. Increasing daylength was positively correlated to increased stem elongation in both ecotypes. Leaf length and area for shade (prairie) plants was significantly altered with increased photoperiods, whereas sun (alpine) plants exhibited minimal leaf expansion in response to increased photoperiod. Increased ethylene evolution in the alpine genotype during rapid stem elongation and extended photoperiods suggests that ethylene plays a growth regulatory role in this sun-adapted genotype. The prairie genotype evolved less ethylene during these same periods, indicating either a diminished requirement for elevated ethylene to effect elongation and leaf expansion responses or possibly increased ethylene sensitivity because of interactions with other hormones, such as gibberellin or auxin. The sun genotype consistently produced more ethylene than the shade genotype under all photoperiod treatments. We conclude that photoperiod alters stem elongation and leaf expansion responses; similar trends were observed for extended photoperiods as were observed for shaded conditions, specifically low light intensity (photosynthetically active radiation) conditions. Further, ethylene levels altered during these responses, especially in sun-adapted alpine plants, which suggests that ethylene is involved in these growth responses.

Leaf growth and senescence rates of three pasture grasses and wheat

2013 ◽  
Vol 64 (7) ◽  
pp. 660 ◽  
Author(s):  
Helen G. Daily ◽  
Peter A. Lane ◽  
Shaun N. Lisson ◽  
Kerry L. Bridle ◽  
Stuart A. J. Anderson ◽  
...  
Keyword(s):  
Life Cycle ◽  
Prescribed Burning ◽  
Linear Models ◽  
Growth Models ◽  
Leaf Growth ◽  
Leaf Length ◽  
Grass Species ◽  
Leaf Position ◽  
Turnover Rates ◽  
Leaf Turnover

A glasshouse study was conducted under ideal conditions to determine leaf appearance, elongation, and senescence rates along with life span and leaf length characteristics of four grass species: wheat (Triticum aestivum L.), brown back wallaby grass (Rytidosperma duttonianum (Cashmore) Connor and Edgar), phalaris (Phalaris aquatica L.), and annual ryegrass (Lolium rigidum Gaud.). This study provided a comprehensive characterisation of leaf turnover rates for the entire life cycle of these grasses, some of which are poorly characterised. Importantly, leaf senescence rate has been captured in the same conditions as the other leaf rates of the life cycle. Leaf position proved to be a significant explanatory variable in each of the leaf turnover rates. The relationships between leaf position and the components of leaf turnover were most commonly represented by non-linear models. Further studies may be necessary to validate these statistical models to field situations. However, this information will be useful to calibrate the senescence algorithms of plant growth models in agricultural decision support tools, which may then be applied to simulation studies including the assessment of grass curing for planning activities such as resource allocation, wildfire suppression, and execution of prescribed burning programs by fire management agencies.

PASTURE RESPONSES TO GRAZING MANAGEMENT IN HILL COUNTRY

1984 ◽  
pp. 168-176
Author(s):  
D.F. Chapman ◽  
D.A. Clark
Keyword(s):  
White Clover ◽  
Leaf Growth ◽  
Leaf Length ◽  
Animal Production ◽  
Grazing Management ◽  
Leaf Removal ◽  
Hill Country ◽  
Defoliation Frequency ◽  
Tiller Density ◽  
Leaf Appearance

Components of growth and defoliation of perennial ryagrass and browntop tillers and white clover stolen apices ware measured for 12 months in hill pastures set stocked (SS) or rotationally grazed (RG) with sheep. Leaf appearance intervals of the grasses were unaffected by grazing management. Tiller densities were greater under SS (annual mean 29,700 total tillers/m' cf. 20,100/m* under FIG), compensating for greater leaf extension rates and lamina lengths of individual tillers under RG. White clover leaf appearance intervals were similar under both managements except in summer when RG was superior to SS during 3 grazing rotations. Defoliation of grass tillers was more frequent under SS when rotation lengths exceeded 3 weeks, but more severe (in terms of leaf length removed) under RG throughout the year. These mechanisms, combined with tiller density differences.contributed to the likelihood of equal leaf removal per unit area under both managements. Some advantage to RG in ryegrass leaf growth and total leaf removal was indicated but the differences were small and unlikely to affect animal production. White clover leaf removal was similar under both managements. Grazed swards are dynamic and can change rapidly under different grazing managements; however, at acceptable levels of pasture utilisation, the dominant responSes appear to maintain an equilibrium in leaf growth. Thus the use of other procedures, e.g. fertiliser application and increases in stocking rate, in conjunction with management changes is required to substantially alter pasture and animal production. Keywords: hill country, grazing management, pasture productivity, perennial ryegrass, browntop, white clover, leaf growth, tiller density, defoliation frequency, defoliation severity.

Effects of temperature on leaf growth in corn (Zea mays)

1982 ◽  
Vol 60 (9) ◽  
pp. 1647-1652 ◽  
Author(s):  
M. R. Thiagarajah ◽  
L. A. Hunt
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Leaf Growth ◽  
Growth Characteristics ◽  
Leaf Expansion ◽  
Specific Leaf Weight ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Effects of temperature on certain leaf-growth characteristics are described for corn (Zea mays L.) hybrid A498 × CG10 grown at 62 nE cm−2 s−1 irradiance (400–700 nm). The rate of leaf expansion declined from a maximum at the earliest measurement stage to zero sometime after the ligule was exserted. The number of visible leaves with actively growing laminae at any stage of ontogeny was constant over day/night temperatures of 15/10, 25/20, 30/25, and 35/30 °C, but increased from three to six between the appearance of the 7th and 13th leaves. Rate of leaf appearance was increased by temperature, from 0.19 leaves per day at 15/10 °C to 0.58 leaves per day at 30/25 °C. However, rate of leaf appearance only increased to 0.60 leaves per day at 35/30 °C. Areas of successive leaves increased to 842 cm−2 at (optimal) 25/20 °C and 772 cm−2 at 30/25 °C for leaf 11, and then decreased to leaf 15. Specific leaf weight (lamina weight/lamina area) increased throughout ontogeny and decreased with increasing temperature.

Water stress affects the productivity, growth components, competitiveness and water relations of phalaris and white clover growing in a mixed pasture

1992 ◽  
Vol 43 (3) ◽  
pp. 659 ◽  
Author(s):  
L Guobin ◽  
DR Kemp ◽  
GB Liu
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
White Clover ◽  
Leaf Growth ◽  
Leaf Water ◽  
Water Potentials ◽  
Relative Water ◽  
Dry Conditions ◽  
Leaf Appearance ◽  
Water Contents

The effect of water stress during summer and recovery after rain on herbage accumulation, leaf growth components, stomatal conductance and leaf water relations of white clover (Trifolium repens cv. Haifa) and phalaris (Phalaris aquatica cv. Australian Commercial) was studied in an established mixed pasture under dryland (dry) or irrigated (wet) conditions. Soil water deficits under dry conditions reached 150 mm and soil water potentials in the top 20 cm declined to nearly -2 MPa after 50 days of dry weather. Water stress severely restricted growth of both species but then after rain fell, white clover growth rates exceeded those of phalaris. Under irrigation, white clover produced twice the herbage mass of phalaris but under dry conditions herbage production was similar from both species. Leaf appearance rates per tiller or stolon were slightly higher for white clover than phalaris but were reduced by 20% under water stress in both species. Leaf or petiole extension rates were more sensitive to water stress than leaf appearance rates and declined by 75% in phalaris and 90% in white clover. The ratio of leaf or petiole extension rates on dry/wet treatments was similar for both species in relation to leaf relative water contents, but in relation to leaf water potentials phalaris maintained higher leaf growth rates. Phalaris maintained a higher leaf relative water content in relation to leaf water potentials than did white clover and also maintained higher leaf water potentials in relation to the soil water potential in the top 20 cm. Stomata1 conductances for both species declined by 80-90% with increasing water stress, and both species showed similar stomatal responses to bulk leaf water potentials and leaf relative water contents. It is suggested that the poorer performance of white clover under water stress may be due principally to a shallower root system than phalaris and not due to any underlying major physiological differences. The white clover cultivar used in this study came from the mediterranean region and showed some different responses to water stress than previously published evidence on white clover. This suggests genetic variation in responses to water stress may exist within white clover. To maintain white clover in a pasture under dry conditions it is suggested that grazing practices aim to retain a high proportion of growing points.

Effects of Temperature on Leaf Expansion in Sunflower

1982 ◽  
Vol 9 (2) ◽  
pp. 209 ◽  
Author(s):  
HM Rawson ◽  
JH Hindmarsh
Keyword(s):  
Field Studies ◽  
Leaf Expansion ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Leaf Position ◽  
Leaf Emergence ◽  
Temperature Regimes ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
Relative Change

Five commercial cultivars of sunflower were grown in cabinets at three temperature regimes, 32/22, 27/17 and 22/12°C, and with 15-h and 11-h photoperiods, and expansion of leaves 5-15 was followed. Leaves appeared faster with increasing temperature (0.022 leaves day-1 °C-1) and with increasing daylength. Areas of individual leaves increased linearly up the plant profile and, although final area per leaf (Amax) decreased with increasing temperature, the relative change was similar for each leaf position. Cultivars maintained their ranking for Amax across temperatures, and these rankings agreed with those in previous field studies. Within each temperature regime, both the expansion rate of leaves and the duration of expansion increased with leaf position. As temperature increased, leaves grew for shorter periods with a change of 1.04 days °C-1, but under the photon flux density used (500 �mol m-2 s-1, or about 25% full sunlight) expansion rates were greatest at the lowest temperature. Expansion rates were only one-third of those in field studies at comparable temperatures, but durations were similar. Cultivars that achieved the largest Amax did so via faster rates of expansion and not via longer durations: only one cultivar differed from the mean (20 days) duration of leaf expansion. All cultivars reached floral initiation progressively earlier with extension of photoperiod from 10 to 15 h, with the change for the most sensitive cultivars being 8 days and for the least sensitive 5 days. Rates of leaf emergence were linked with this sensitivity.

scholarly journals Effects of accumulated temperature on growth curve of Gynostemma pentaphyllum stem and leaf under the conditions of Simulated light under the forest

2021 ◽  
Author(s):  
Chunyao Dun ◽  
Wan Songsheng ◽  
Li Shuanglong ◽  
Wu Daikun
Keyword(s):  
Growth Curve ◽  
Leaf Growth ◽  
Three Dimensional ◽  
Logistic Function ◽  
Leaf Number ◽  
Stem Length ◽  
Suitable Habitat ◽  
Three Dimensional Model ◽  
Gynostemma Pentaphyllum ◽  
Accumulated Temperature

The effects of accumulated temperature on the growth curve and leaf number growth curve of Gynostemma pentaphyllum were studied. The growth curve of twigs and strands were studied by curve regression analysis. The results showed that the growth of Gynostemma pentaphyllum Leaf growth curve was optimized, and the growth curve of stem and leaf of Gynostemma pentaphyllum was established, and the curve was fitted and analyzed. Three - dimensional model of the effect of accumulated temperature on the stem length and leaf number of Gynostemma pentaphyllum . The results show that the stem length L and the accumulated temperature t of the strands are in the logistic function, the mathematical model was L=-112.69/(1+(t/892.1) 3.31 )+130.54, the number of gibbere leaf number n is logistic function with the accumulated temperature t, The model was n=-27.86/(1+(t/1159.77) 0.26 )+30.37, and the growth model could reflect the dynamic growth of Gynostemma pentaphyllum growth. The experimental results provide a theoretical basis for choosing suitable habitat for Gynostemma pentaphyllum under the forest.

scholarly journals Effects of nitrogen on development and growth of the leaves of vegetables. 3. Appearance and expansion growth of leaves of spinach

1995 ◽  
Vol 43 (2) ◽  
pp. 247-260
Author(s):  
H. Biemond
Keyword(s):  
Leaf Area ◽  
Leaf Size ◽  
Field Trials ◽  
Leaf Expansion ◽  
Mature Leaf ◽  
Leaf Emergence ◽  
Number Of Leaves ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Main Factor

In a series of greenhouse and field trials, spinach cv. Trias plants were supplied with different amounts of N fertilizer in various split applications. Rates of leaf emergence and expansion were recorded, as well as final leaf size. The rate of leaf appearance varied between 0.16 and 0.57/day across experiments, but was hardly affected by N treatment. The rate of leaf expansion and mature leaf area increased with leaf number, reaching maximum values at leaf pair 3+4 or 5+6 and decreasing subsequently. Both characteristics were positively correlated with N supply. The duration of expansion was not influenced by N treatments and varied between 15 and 30 days in most experiments. The rate of leaf expansion was the main factor determining mature leaf size. Specific leaf area over all green leaves slowly decreased with time in most experiments and was around 300 cmsuperscript 2/g. As the differences in the number of leaves were small, the differences in total green leaf area per plant resulted from differences in the areas of individual mature leaves.

LIGHT-STIMULATED LEAF GROWTH ON INTACT AND EXCISED BEAN PLANTS (PHASEOLUS VULGARIS L.). II. EFFECT OF LIGHT DURATION AND TIMING OF APPLICATION

1999 ◽  
Vol 47 (3) ◽  
pp. 147-152
Author(s):  
Shimon Lavee ◽  
Elizabeth Van Volkenburgh ◽  
Robert E. Cleland
Keyword(s):  
Phaseolus Vulgaris ◽  
White Light ◽  
Leaf Growth ◽  
Relative Rate ◽  
Red Light ◽  
Leaf Expansion ◽  
Leaf Elongation ◽  
Leaf Unfolding ◽  
Light Duration ◽  
Partial Unfolding

The dependence of bean (Phaseolus vulgaris L. cv. Contender) leaf unfolding and expansion on light has been explored in intact and excised plants by varying the duration and timing of exposure to white light. Plants were grown for 10 days in dim red light (RL), and then some were excised. Both the intact and the excised plants were then exposed to varying white light (WL) treatments. In continuous WL, leaf unfolding began after 8 h, and was maximal after 36 h. For plants exposed to short WL treatments, as little as 2 h WL elicited partial unfolding when leaves were returned to RL and measured after 60 h. The relative rate of leaf elongation was most rapid during the first 2 h of WL and it rapidly decreased during the following 6–8 h. An 8 h exposure to WL followed by 52 h RL produced only a slightly lower leaf expansion than continuous WL for 32 h. Leaf elongation after 24 h constant WL irradiance was no longer light-dependent. The response of leaves on excised plants to WL was progressively less if treatment was delayed for 24 h after excision. In contrast, leaves on intact plants did not lose their ability to respond to light even after 48 h in the dark. The ability of leaves on intact or excised plants to elongate in RL decayed rapidly after day 10. These results indicate that light-stimulated leaf expansion in beans is mediated by some factors whose transport to the leaves is influenced by the presence of roots.

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